Indicating means for instruments.



H. P. DAVIS & P. MAOGAHAN.

INDIGATING MEANS FOR. INSTRUMENTS. APPLICATION FILED 00T.21, 1905.

920,927. g Patented May 11, 1909.

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wpmssfl I I I INENT R6.' mgwgw V I A TTORNEY H. P. DAVIS dz 1?. MAOGAHAN. INDIGATING MEANS FOR INSTRUMENTS.

APPLICATION FILED 0021.21, 1905.

920, 927. Patented May 11, 1909.

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WITNESSES: -zwtt/ uni HARRY P. DAVIS AND PAUL lldACGAIIAN, OF PITTSBURG, PENNSYLYANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC dpMANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

'nvnics'rme Mann's FOR msrnmnnrs.

Specification of Letters Patent Patented May 1 1, 1 909.

Application filed October 21, 1905. Serial No. 283,850.

To all whom it may concern:

Be it known that we, HARRY P. DAv s and PAUL MAoGAnAN, citizens of the United States, and residents of Pittsburg, in the county of Allegheny and State of Pennsylwhich may be readily and advantageously comb ned with other parts.

In Patent No. 685,155, granted October 22d, 1901, to Paul M. Lincoln, is set forth and claimed a synchronisin indicator com prising relatively movable members one of which is provided with a single winding that 'is adapted to be connected to one source of alternating current and the other of which is provided with two windings that are ada ited to. be connected to another source of i terf n'airbmg current. Means are also provided lor 1i. .idisplacing the phase of the current in one of Li lie windings oi the second member with re- Hi; spect to that in the other winding, and such means preferably comprises a non-inductive tion and illustrating the circuit connections thereof.

The stationary magnetizable core 1 is rovided with a windingZ that is-connecte between distributing conductors 3 and 4 lead istributing vania, have invented certain new and useful ing from a suitable source 5 of alternating Improvements in Indicating ltieans i or Incurrent energy which is to be caused to operstruments, of which the following is a speciate synchronously with another suitable fication. source 6 of alternating current energy. An 10 Our invention relates to indicating means annular magnetizable core 7 is rotatably for instruments, and particularly to, such mounted within the ma netic iniiuence of means as may be applied to syncl'ironisni inthe stationary core 1 an is prov ded with dicators. two windings that respectively comprise The object of our invention is to provide coils 10 and 11 and 12 and 13 which are dis- 15 an improved indicator for the purpose set posed alternately upon the core 7. One terl'orth which shall be inherently useful and minal of each of the windings is connectedto other terminal of which is connected to distributing conductor 21 of the source 6. Slip ring 16 is engaged by a brush 2 2 which is connected 0 one terminal of each of lam s 23 and 2 the remaining terminals of whic 1 are -irresistance that is connected in series with one i oi.-the windingsand an inductance or choke 35 coil that is connected in series with the other that is composed, preferably, of glass or other transparent or translucent material winding. F or the non-inductive resistance which is connected in series withone of the windings oi' the second chamber, we )ropose to employ incandescent lamps, whic I serve 0 also as means for illuminating the dial oijthc instrument, and we further provide the indieating arm which is carried by theinovable member with a lamp which is connected in serles wlth the stationary lamps and one of 45 the windings of the second member.

Our invention is illustrated in the accompanying drawings, Figure 1 of which is a view, in front elevation, of'an instrument constructed in accordance therewith, a per- 50 tion of the front plate being broken away.

Fig. 2 is a view, partially in side elevation and partially in section, of the instrument shown in Fig. 1, and Fig. 3 is a diagrammatic view of a svstem embodvimz our invenand may bear any marks for indicating purposes that may be desired, such, for example, as that shown at 30 and the letters S and E. The lamps 23 and 24 thus serve both as resistance in the circuit of the coils 10 and 13 and as illuminating means for the dial of the instrument. 1

The rotatablemember is provided with an indicator arm 27 which carries, at its outer end, a lamp 28 that is connected between terminal 29 of coil 10 and slip-ring 16 and also serves asa non-inductive resistance in the circuit of the coils 10 and 13, as wall as illuminating means for the indicator arm.

When it is desired to cause either of the sources 5 and 6 to operate in synchronism with the other source which is alread in operation, the instrument is connecte as indicated in Fig. 3, with the sources by closing the switches 31 and 32. If the sources are d, the lamp ill occupy s. nosition direct in the rear of 'thc snarl: 39 on tin: dislplatc 25, but if the l'rv-zniency of the nniehuie ready in operation is loss than that oi the other, the min 27 and ihc lsinp will be rototed in clockwise direction. if the ire quency of the inochincto be synchroniznd is greater than that of the machine :llIPfKlX in o )eration, the clockwise direction. The speed of rotation of the indicator arm and the lamp will be proportional to the difference in frequency and voltage of the two sources, so that, as the-two sources zu'iproach synchronous operation, the

pointer will decrease in speed and at synchronisni will occupy a position dircctly in front of the mark 30.

' It is of course understood that :i singlc stotionsry him?) not) be employs l for iihnninat ing the dial, or any other suitable number arm and that the lamp or lonips upon the in- ('llCtLtOl arm may be connected in circuit 111 on; other suitable manner if it 13 not desired to utilize such hunp 0r lsnlps as additional resistance in the circuit of one of the windings of the movable rncniber.

' While it will gcnerallybc found most expedient to employ lamps as indicating means, it will be readily understood that any other indicating means may be mounted upon the rotatable indicator arm which may or may not include inductive resistance to be connected in circuit with one of the. windings of the movable member.

Other modifications of the details of construction andof the arrangements of the eircults may be employed without departing from the spirit'iof the invention.

As we are not aware that the movable itl'lils or pointers of indicating instruments have i heretofore been provided with illuminsting means, we have fully set forth such structure i in the specification and covered it broadly in the appended claims.

Vvc clann as our invention:

'1. Tho combination with two sources oi alternating current, and relatively movable members one of which is provided with i winding connected to one of the sources and in synehrcnisin when the switches the other of which. provided wiih \i'inding s connccted to ihr oiher source, oi on nnhczitor arin open-nod by onv ol the members, :i lain r-urricd h said :irin and connected in the -;:n= which is heing synchronized with the one cl (hit of Ulll' oi the windings. or" the second member, and stationary lumps also rouin-rlod in tin t-Ihlil rirruit to serve as rcsisi- :nu-c lll1 l as illuminating menus.

2. 'lhc combination with two soill'ms ol' 5 illl l'ililliill curreni and rclotivcl movable v h 7 hunp Wlll rotate in :1 counterinsunbvrs one of which is PI'OVldQd with n winding ronnmztwl in one of tho sources and the othor of which is provided with uindings connected to the othcrsourro, of on indicator irni operated by one oi" the members, and :i lamp rurricd ihcrchy arid conncctcd in circuit with one oi the windings of the second member to serve 21s a resistance :thll as an i indicator.

3. The ronihiinuion with relatively niov- Ruble members: one of which is provided with l n. single magnetizing winding and the. other may be employed; that more than one lain 1 may be mounted upon the. movable indicator j us at rs-sistsnce and as an illuminating means.

The combination with rohitivoly niovable members onoof which is provided with a single magnetizing winding and the other of which is provided with a plurality of such windings, of an indicatondisl, one or niorc lamps connected in circuit with one of the windings of the second member and serving both as resistance and as means for illuminating the dial, an indicator arm operated. by one of the members, and an illuminated indicator curried thereby and energized from the circuit of one ol' the windings of the second member.

in testimony whereof, we have hereunto subscribed our names this 13th day of ()ctobcr, 1%05.

HARRY P. DAVlS. PAUL INiAcGAl lAN.

i Vitnessrs 11.55 to Harry l. Davis:

a). E. Sursns, Eisner hurls.

.w'itncsscs as to Paul him-(hrhon:

S. M. TRUXAL, Humor limos. 

